Dynamo-electric machine.



M. WALKER.

DYNAMO ELECTRIC MACHINE.

APPLICATION FILED DBO. 6, 1907.

1 1 1 5,352. l Patented oon. 27, 1914.

WITNESSES: INVENTUR BY, Mdm Mmm,

UNITE STATES PA. FFCE.

MILES WALKER, F OLD TBAFFOR-D, ENGLAND, ASSIGNR, BY JESNE ASSGNMENTS,

TO WESTINGHOUSE ELECTREG c MANUFACTURING' COMPANY, @F EAST PITTS- BURGH, PENNSYLVANIA, A CORPORATON PENNSYLVNA.

T0 all whomY fir' may concern,

Be it known that l, Minne Wannen a subject of the King of Great Britain,l and a resident of Old Trafford, Lancester county, England, have invented new and useful Improvement in lynamo -Electrlc Machines, of which the following is a specification.

My invention relates to dynamo-electric machines havingcommutators and particularly to machines of this kind which are intended for operation at high speeds.

Diiiiculties are often encountered in connection with the commutation of the currents generated by high-speed machines on account of the comparatively large diference of potential which exists between adj acent commutator bars by reason of the comparatively small number of coils necessary lto .produce the electromotive force desired in the external circuit.

The present invention has for its object to provide means whereby a larger number of commutator bars may be employed with a given winding than would otherwise be possible. The desired result is accomplished by connecting the main armature coils to commutatorbars separated by one or more intermediate bars and connecting the intermediate bars to points of suitable potential in an auxiliary winding disposed on the armature core.

In order that the 'potential diiierence hetween adjacent commutator bars maybe uniform, I provide an auxiliary winding so disposed that each portion which is connected between adjacent commutator bars is subjected to a smaller amount of magnetic flux than the corresponding portion oi the main winding.v

In the accompanying drawings, Figure l is a diagram of connections for the armature winding of a dynamo-electric machine embodying my invention; Fig. 2 is a longitudinal sectional view of the armature corresponding to Fig. l. Fig. 3 is a view corresponding to Fig. l, but showing a winding of modiiied construction. Fig. e is a cross sectional view of a fragment of an armature showing the conductors in a single slotwhen the winding shown in Fig.' 3 is employed.

Referring to Figs. l and 2, the auiziliamf' Speccaticn or" tctters Patent.

Application filed Eeceinber 6, i907.

Patented 9ct. 2?, 19h/.

suini no. 405,427.

winding 1i is of the drum type, the con ductors 23, 24, 25, 2G, etc., of which extend over only halt the length of the armature core, a circumferential groove l0 .being provided in the core tc accommodate the end coni'icctions of the auxiliary winding which has double the number of turns of the main winding 5"* and generates the same electrornctivc force.

As shown in Fig. l, there are two narrow coini'nutator bars 27, 28 and 29, 30 between .the eiiect of the arrangement is such as to double the number of bars in the commus tator. l

A further modication is illustrated in Figs. 3 and el, in which the adjacent bars Z-27 and 8-29, respectively, which are of the same potential, as shown in Fig. l, are

replaced by single bars 7, 8, 9, the commutator bars being made of equal width. In this arrangement, the auxiliary winding 1lb has the same number or" turns as the main winding 5b, one end 31, 32, 33 of each turn being connected to the corresponding end 3e, 85, 36 of a turn or the winding and the remaining end 8'?, 38, 39 of each turn of the auxiliary winding being connected to an intermediate commutator bar 17, 18, 19.

It will be understood that the arrangements shown in Figs. 3 and 4 may be so modied as to accommodate a greater number or" 'intermediate commutator bars between each pair of the commutator bars connected to the, main winding, by altering the number of turns inthe auxiliary winding and the amount of flux to which each turn thereof is vsubjected and it-is desired that the invention be not regarded as .confined to the specific, arrangements herein shown, which, are given for the purpose oit illustration. and description and may be varied los Gopien of this patent may be obtained for ve cents each, by addressing the Without departing of the invention.

I claim as my invention: 1. An armature for a commutator typ dynamo-electric machine comprising a slotted core, main conductors located in the core slots and connected to the commutator bars which are separated by one or more intervening bars, and auxiliary conductors disposed in the main core slots for substantially one-half the lengths of said slots and having points of suitable potential connected to said intervening bars to reduce the potential difference between adjacent from the spiritiand scope commutator bars.

2. An armature for commutator type dynamo-electric machines comprising a slotted core, main conductors located in the core s lots and connected to commutator bars which are separated by intervening bars and auxiliary conductors disposed in the main core slots for' substantially one-half vof the lengths of said slots and having their -respective ends connected to the main Winding conductors andl to the intervening commutator bars.

3. An armature for commutator type dynamo-electricmachines having a main winding connected to commutator lbars which are separated by intervening bars, and

an auxillary winding which is sub- ,a portion of the magnetic winding connected to commutator bars- Which are separated by intervening bars 'and an auxiliary Winding the conductorsv of which extend over only one-half the length of the armature core', each alternate conductor of said auxiliary Winding being connected to an intervening commutator bar, and the remaining conductors of said Winding being connected to conductors of the main Winding.

5. An armature for commutator type dynamo-electric machines \comprising a core, main coils connected to commutator, bars which are separated by intervening bars, and auxiliary coils disposed-in proximity to the main coils but having corre.- spondingly located parts only one-half their lengths, each ofsaid' auxiliary coils having one end connected to a conductor of the main Winding and its other end connected to an intervening commutator bar.

In testimony whereof, I have'heieunto subscribed my November, 1907.

- MILES WALKER.

Witnesses:

SARAH E. ASHLEY, EvnmNE WALKER. g

Commissioner of Patents,

Washington, D. C.

name this eleventh dayof 

